Gear drive system having slip-in spacer and method of use

Abstract

A gear drive system including a housing having a cavity and first and second opposed, axially aligned output shafts, the first and second output shafts having first and second gears, respectively, mounted thereon. At least one of the first and second output shafts has a predefined range of travel in the longitudinal direction of the first and second output shafts. A gear assembly is in operative engagement with the first and second gears. A spacer is positioned between the housing and one of the first and second gears. The spacer is configured to preclude movement of the at least one of the first and second output shafts through at least substantially all the predefined range of travel. A cover covering the cavity retains the spacer in position between the housing and the one of the first and second gears.

I claim:  
     
       1. A gear drive system comprising: 
       a housing having a cavity, a service port in communication with the cavity, and a pair of opposed, apertures in communication with the cavity, each of the apertures aligned along a longitudinal axis of the housing;  
       a first output shaft positioned in one of the apertures and being at least substantially aligned with the longitudinal axis of the housing, the first output shaft having a first inboard end within the cavity;  
       a second output shaft positioned in the other of the apertures and being at least substantially aligned with the longitudinal axis of the housing, the second output shaft having a second inboard end within the cavity;  
       a first gear positioned on the inboard end of the first output shaft;  
       a second gear positioned on the inboard end of the second output shaft, at least one of the first and second gears having a predefined range of travel in the direction of the longitudinal axis of the housing;  
       a gear assembly within the cavity in operative engagement with the first and second gears, the gear assembly for transferring power to the first and second output shafts via the first and second gears;  
       a spacer positioned proximate the service port and between the housing and one of the first and second gears, the spacer being configured to preclude movement of the at least one of the first and second gears in a direction along the longitudinal axis of the housing through at least substantially all the predefined range of travel; and  
       a cover for covering at least a portion of the service port, the cover having a land, the land being proximate the spacer and retaining the spacer in position between the housing and the one of the first and second gears.  
     
     
       2. The gear drive system of  claim 1 , wherein the spacer has a thickness in a direction of the longitudinal axis, the thickness being approximately equal to the predefined range of travel to preclude movement of the at least one gear in the direction of the longitudinal axis of the housing. 
     
     
       3. The gear drive system of  claim 1 , wherein the spacer includes a contact surface positioned between the one gear and the housing, the contact surface being adjacent the land when the cover is covering thy service port. 
     
     
       4. The gear drive system of  claim 1 , further including a circumferential bearing positioned on the one of the first and second output shafts between the spacer and the one of the first and second gears. 
     
     
       5. The gear drive system of  claim 1 , wherein the housing is unitary. 
     
     
       6. The gear drive system of  claim 1 , wherein the spacer has a slot therein that extends in a direction transverse to the longitudinal axis, the one of the first and second output shafts being positioned within the slot. 
     
     
       7. The gear drive system of  claim 6 , wherein the spacer includes first and second fingers defining the slot. 
     
     
       8. The gear drive system of  claim 7 , wherein the spacer includes a pair of recesses, each recess substantially opposed to one of the first and second fingers. 
     
     
       9. A gear drive system comprising: 
       a housing having a cavity, a service port in communication with the cavity, and a pair of opposed, apertures in communication with the cavity, each of the apertures aligned along a longitudinal axis of the housing;  
       a first output shaft positioned in one of the apertures and being at least substantially aligned with the longitudinal axis of the housing, the first output shaft having a first inboard end within the cavity;  
       a second output shaft positioned in the other of the apertures and being at least substantially aligned with the longitudinal axis of the housing, the second output shaft having a second inboard end within the cavity;  
       a first gear positioned on the inboard end of the first output shaft;  
       a second gear positioned on the inboard end of the second output shaft, at least one of the first and second gears having a predefined range of travel in the direction of the longitudinal axis of the housing;  
       a gear assembly within the cavity in operative engagement with the first and second gears, the gear assembly for transferring power to the first and second output shafts via the first and second gears;  
       a spacer positioned proximate the service port and between the housing and one of the first and second gears, the spacer being configured to preclude movement of the at least one of the first and second gears through at least substantially all the predefined range of travel;  
       a circumferential bearing positioned on the one of the first and second output shafts between the spacer and the one of the first and second gears, the spacer including first and second fingers, the first and second fingers each including a recess for receiving the bearing; and  
       a cover for covering at least a portion of the service port, the cover having a land, the land being proximate the spacer and retaining the spacer in position between the housing and the one of the first and second gears.  
     
     
       10. A method of assembling a gear drive system comprising the steps of: 
       positioning a first output shaft in a first aperture in a housing, the first aperture being in communication with a cavity within the housing;  
       positioning a first gear on an inboard end of the first output shaft, the first gear being within the cavity;  
       positioning a gear assembly in the cavity of the housing, the gear assembly being operatively engaged with the first gear;  
       positioning a second output shaft in a second aperture in the housing, the second aperture being at least substantially aligned with, and opposed to, the first aperture, the second aperture being in communication with the cavity;  
       positioning a second gear on an inboard end of a second output shaft, the second gear being within the cavity, the gear assembly being operatively engaged with the second gear;  
       slidably positioning a spacer within the cavity in a direction generally transverse to the longitudinal axis between one of the first and second gears and the housing;  
       positioning a cover over at least a portion of a service port of the housing, the service port being in communication with the cavity, the cover having a land, the land being proximate the spacer and retaining the spacer in position between the housing and the one of the first and second gears.  
     
     
       11. The method of  claim 10 , wherein the step of slidably positioning the spacer within the cavity further includes orienting the spacer substantially transverse to a longitudinal axis of the housing. 
     
     
       12. A gear drive assembly comprising: 
       an elongate housing having a cavity and a pair of opposed apertures in communication with the cavity, the apertures being aligned with a longitudinal axis of the housing;  
       at least one output shaft extending through at least one of the apertures and having an inboard end located within the cavity, the output shaft being at least substantially aligned with the longitudinal axis;  
       a gear fixedly connected to the inboard end of the output shaft for rotation therewith, the gear and the output shaft having a predefined range of travel in a direction of the longitudinal axis to facilitate assembly of the gear drive assembly within the elongate housing; and  
       a spacer located within the cavity between the housing and the gear, the spacer being stationary with respect to the housing and comprising a pair of spaced legs with a slot therebetween for installation on the output shaft in a direction transverse to the longitudinal axis, the output shaft extending through the slot to thereby preclude movement of the gear and the output shaft through at least substantially all of the predefined range of travel.  
     
     
       13. A gear drive assembly according to  claim 12 , wherein the spacer has a thickness in a direction of the longitudinal axis, the thickness being approximately equal to the predefined range of travel.